Reciprocating engine



NOV. 1, 1949 J TRAHIN 2,487,003

RECIPROCATING ENGINE Filed Oct. 13, 1947 v 2 Sheets-Sheet 1 INVENTOR.

John Henry Tr a/7/n ATTORNEY 1949 J. H. TRAHIN 2,487,003

RECIPROCATING ENGINE Filed Oct. 13, 1947 I 2 Sheets-Sheet 2 5 JNVENTOR.

John Hen/y Fab/n o W 4 "A 46% AT TOR/V5) Patented Nov. 1, 1949 RECIPROCATING -ENGINE J ohnrHenrmTrahin, Beaumont, Tex.

Application October '13, 1947," Serial No: 779 608 This invention relates toreciprocating engines and is directed primarily to improvements, the coupling between the-piston rod and the connecting rod.

The-primaryobiect ot the invention is to provide an improved.- mech'an-icalmovement forming an operative coupling between =a- -pistonrod and a --crank -connecting *rod whereb'y an increase in the movement of the connecting rodrelative to the piston rod obtained to thereby increase the mechanical advantage of the engine by increasing the throw-on the-engine crank:

Still another object of etheinvention isto providea novel coupling mechanism" between: a piston rod of a -reciprocatingengine -and' the engine connecting rod whereby a di'fi'erential movement is obtained between the-piston rod and=the con-'- necting rod in sucha manner as to make possible the-employment of a crankhavinga throw greater than would be used" in an engine wherein the usual conventional pivotal 1 coupling at .the cross head is employed; Y

A still further object "of the-invention is to provide an improved cross head construction :for use-in reciprocating engines :or pumps where a cross head is interposed between i a I piston rod and a= connecting rod,: having aneccentric or eccentrics, forming a 'partof the cross head and operatively coupled-- with" adiacent". stationary parts -'of the *engine "to 'beturned Y upon ireciprmv catory movement of the cross head; to impart a slight additional movement I to the engine connecting rod whichis coupled-to"the-eccentric over andabove-the movement given 'tocthepart "of the cross-head to which therpiston rod is conne'cted.

Other objects and advantages of the invention will-become apparent ';as thedescription of the same proceeds and the-invention will be best understood from a consideration of tha following detailed description taken in connection: with the accompanying :drawings forming part of "the specification,- with the understanding; however, that the invention? is not L to be llimited to r the exact "details of construction shown and described since obvious modifications "will locurato aperson skilled in the art;

In the drawings:

Figure-l is a vieW partIy'in' section and partly in side elevation of i aavertical reciprocati'ng engine showing-incorporated therein "the mechanical movement constituting the present-invention.

Figure 2 is a-'-viewpartly' in-"-s'idelevation and partly in "vertical" section ofthe-*same wherein the section of "certain of 'th'e= parts istaken "sub stantiallyuponthe11ne -2+2 ot F igure -1;-

Figure 3 is a detail view on an enlarged iscale of one unit .or block Ofth ecrosssheadshowing the positions of :the eccentric rings when the cross head is in lowered-position;

Figure l. 4 is :a viewwcorresponding .to Figure 3, but .showingvthe positionnof the eccentric rings when the cross headcisinrraised or elevated .position Figure-5 .is va detail .section-Ltaken substantially on the 1ine.5:5 .of Figure 1;

Figure 6 is a martial. transverse (section: :taken of thelplane of line 5L-530f Figural. l

Referring now more particularly to. athedrawsings, Figures. 1 and 2..illustrate :moreJorless ..conventi-onally parts of a. vertical reciprocating steam engine, inassociation with whichthepres entiinvention is illustrated.

While it is =statedtthatrthe illustration-sis of. a vertical reciprocating steamengine it is to be understood: that the .:use of-ithe :invention.v is not to be limited .to an:.engine ofthischaracter as itwill' be readily apparent to those versed-:inthe art that the-invention may' be .employedflin con nection with a pumping: engine. of simii'arxconstruction or in connection:withxanyzmechanical structure or movement wherein: reciprocating movement is translated into rotarylmovement or vice-versa.

In. the structure; illustrated :the numeral. I0 generally; designates axpiston cylinder supported above .andfrom an .enginezbase :l 2 by the vertical, spaced, parallel cross head guides 3.

The .numeral 1 14' designates. the engine crank shaft, the crank being designated-3 .15. v

Disposed Within-the :cylinder l0 )isthe. piston [5" which carries therigidQpistomrod- I 'IWhich extends :downwardly, through the'xusual packing gland: I8? for connection with: the cross head structure which is slidably,mountedzbetween the cross head guides.

The piston rod .1 1 .is in line with theaxis ofuthe crank; shaft l 4 and-perpendicular thereto .as in the. usual. :constructicn:.and; ,theacrank .pin I 8 has coupled therewith OIIGLBDd'JOf thegconnectingflrod l9'.-.

In :accordance with thezpresent invention: there is provided outside of; the 'spaces'occupied by the cross'head guides l3;ao'supportingmeansfor the hereinafter described :rocker i bearingwunits such means bein here shown as in the: form- 0f ifour rails; eachof which is designated 20;: Eachof these rails is adjacent to a cross head-guidel3 and f is spaced.- outwardly therefrom in: a direction perpendicular to the crank sh'aft I 4 While reference-has been made tothe use 'of the individual rails for the support of the hereinafter described rocking bearings, it is to be understood that any other suitable supporting means may be employed if desired, as for example, the cross head guides may be inclosed in a suitable housing the walls of which would then be employed for the support of the bearings.

The numeral 2| generally designates the cross head which provides the coupling between the outer end of the piston rod I1 and the connecting rod l9.

In the embodiment of the invention herein illustrated the cross head structure embodies the two units 22 which are here illustrated as being in the-form of rectangular boxes which are suitably grooved or channeled along each of four parallel corners, as indicated at 23, to receive correspondingly shaped corners of the cross head guides, whereby the units 22 are maintained for sliding reciprocatory movement on and between the guides.

The units 22 of the cross head structure are here shown as hollow box like units and this construction is preferred for lightness. However, it will be readily apparent that such units may be of solid form or in the form of blocks, if desired.

The units 22 rest one upon the other as shown in Figures 1 and 2 and are secured or coupled together for unitary movement in any suitable manner as, for example, by the use of the bolts 24.

Each of the cross head units 22 has two opposite end walls 25 in the center of which is formed the circular opening 26, in which is fitted for turning movement an eccentric ring 21.

The ring 21 has the opening 28 thereof eccentrically located with respect to its periphery and within this eccentric opening is fitted the inner eccentric ring 29, the eccentric irmer edge or opening 30 of which is concentric with the periphery of the outside eccentric ring 21 and is in the exact center of the end wall 25.

Extending through each unit 22 is a wrist pin 3|, each end of which has the bearing head 32 which is mounted in the opening 30 of the inner eccentric ring 29. Accordingly it will be seen that the wrist pin 3| extends through the exact center of the box or unit 22.

In the construction here illustrated, the upper box unit has the top opening 33 through which the piston rod extends downwardly into the unit for connection with the wrist pin 3| thereof.

The lower box unit 22 has a similar opening 34 in its bottom wall through which extends upwardly the connecting rod IQ for connection with the wrist pin 3| of the lower unit.

Each pair of eccentric rings or eccentric wedges 21 ad 29 has associated therewith a pair of rocker arms 35. One arm of each pair is connected with the inner eccentric ring or wedge 29 at the low side of the eccentric, by which is meant the side between the bearing 32 and the periphery of the inner eccentric ring where the periphery comes nearest to the bearing. The other arm 35 of the pair is secured to the outer face of the outer eccentric ring or wedge 21 at the side thereof remote from the low side of the ring 29. This description of the locations of the ends of the arms 29 applies, of course, when the arms are directly in alignment as shown in Figure 1, where the cross head is in the midway position between the upward limit and downward limit of its movement.

Each of the rocker arms 35 extends outwardly through a rocker bearing which is generally designated 36. Each of these bearings comprises 4 a box 3! having the end aligned openings 38 for the extension of an arm through the box and rotatably mounted within the box upon opposite sides of the arm 35, here shown as the top and bottom sides, are anti-friction elements 39, here shown as roller bearings. The ends of these roller bearings are rounded or pointed as indicated at 40 and seat or engage in correspondingly shaped recesses in the opposing walls of the box so that as the arm 35 reciprocates back and forth through the bearing box the anti-friction elements will turn and therefore reduce the friction to a minimum.

Each of these boxes has secured thereto a pivot stud or trunnion 4| which passes through and is rotatable in a suitable opening in the adjacent bearing supporting rail 20, the outer end of this stud receiving a nut 42 which holds the bearing box in the desired position.

The bearing boxes or bearing units 36 are located so that when the cross head is inits midway position as previously stated, where the pairs of arms 35 are in direct alignment transversely of the cross head guides l3 and rails 20, the centers of the pivots or trunnions 46 for the boxes or bearing units will lie in the same plane as the aligned arms.

In the operation of an engine of the character here illustrated, as the cross head moves up and down or reciprocates, the eccentric rings or circular wedges 2! and 29 will be turned one around the other as illustrated in Figures 3 and 4. This turning action is brought about by the engagement of the arms 35 in the pivoted bearing units or guides 38. Since the positions of these bearing guides remains fixed as regards up and down movement while the circular wedges connected to the inner ends of the arms 35 are traveling back and forth in a straight path, it will be seen that such circular wedges will be turned. While the extent of movement of the units 22 of the cross head is the same as that of the piston and piston rod |6--||, by the rotary action of the eccentrics particularly the eccentrics of the lower unit to which the connecting rod 9 is attached, the center of the wrist pin 3| which is connected with the connecting rod l9 and the piston rod I1 and units 22 will have a difierential movement. Accordingly as the piston rod and cross head units 22 i move down the center ofv the wrist pin 3| with which the connecting rod I9 is connected will move down somewhat faster because of the action of the circular wedges or eccentric rings, and accordingly the crank l5 can be of a length to have a greater throw, which is determined by the movement difierential between the lower wrist pin 3| and the connecting rod than would be possible if the connecting rod and piston rod were coupled to a cross head Of the usual or conventional form,

With the present construction it is possible to have a crank with a 4 inch throw operated by a piston having a 6 inch stroke. Under normal practice a 6 inch stroke piston could operate only with a crank having a 3 inch throw. Accordingly a gain of an inch and one half in the throw of the crank is obtained and consequently the mechanical advantage is greatly increasedvso that a greater amount of work can be accomplished with an engine constructed in accordance with the present invention or employing a cross head construction of the character herein disclosed.

While an illustration .has been made of the cross head employing two separate boxes'or units 22 use may be made, if desired; of a cross head employing only a single box and a pair of arms at each end. In such construction, however, the piston rod I! would be attached directly to the top of the box or cross head unit and the connecting rod I9 would extend into the unit and be attached to the wrist pin 3 I. With this construction or arrangement a corresponding action would be obtained as described in connection with the use of the two cross head units shown and described.

I claim:

1. In a mechanism of the character stated, a reciprocable driven element, a member supported for rectilinear movement and operatively coupled with said element to move therewith, a rotatable crank, and a coupling between the member and crank comprising an eccentric supported on said member to turn thereon on an axis perpendicular to the line of movement of the member, means for effecting turning of the eccentric relative to the member upon rectilinear movement of the member, a connecting rod connected at one end to said crank, and a wrist pin coupling between the other end of the connecting rod and the eccentric to turn on the turning axis of the eccentric and move in a straight path with said member.

2. Mechanism for increasing the mechanical advantage in a reciprocating engine having a piston and piston rod, a rotatable crank and a connecting rod attached at one end to the crank; comprising a cross head body attached to the piston rod to reciprocate in a straight path therewith, supporting guides for the body, an eccentric element carried by the body to turn relative to the body on an axis perpendicular to the line of movement of the body, a pivot coupling between the other end of the connecting rod and the eccentric and turning on the same center as the eccentric, and means for effecting positive partial turning only of the eccentric on its axis relative to the body as the body reciprocates.

3. A mechanism of the character stated in claim 2, wherein the said means for effecting the positive partial turning of the eccentric on its axis comprises an arm secured at one end to the eccentric, a guide bearing having the arm extending therethrough, and pivot means of supporting said guide bearing at one side of the cross head body for turning on an axis paralleling the turning axis of the eccentric, the arm being slidable longitudinally through the bearing.

4. Mechanism for increasing the mechanical advantage in a reciprocating engine having a piston and piston rod, a rotatable crank and a connecting rod attached at one end to the crank; comprising cross head guides paralleling the path of movement of the piston and piston rod, a cross head body supported by said guides, the piston beingattached to the body for concerted movement therewith, said cross head body having opposite end Walls spaced apart in a line perpendicular to the path of movement of the piston rod, said end walls having aligned circular openings therein, the axial centers of which intersect the center line of the piston rod, a ring in each of said openings and having an eccentric opening, an eccentric ring in the eccentric opening of each of the first rings, a wrist pin extending transversely through the body and supported at each end eccentrically in an eccentric ring, the other end of said connecting rod being coupled with said wrist pin, an arm attached to each of the first rings and extending laterally therefrom away from the wrist pin, an arm attached to each of said eccentric rings and extending laterally in the opposite direction away from the wrist pin, a bearing guide for each arm and having the arm slidably extended therethrough, and a pivotal support for each bearing guide positioned laterally of the cross head body, the turning axis of the bearing guide pivots being parallel with the wrist pin and in a common plane extending perpendicular to the piston rod and lying midway between the limits of movement for the cross head body.

JOHN HENRY TRAI-DN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 485,557 McMaster Nov. 1, 892 1,308,499 Krutchenreiter July 1, 1919 1,797,493 Baxter Mar. 24, 1931 1,988,57 Rider Jan. 22, 1935 

